The aim of this application is to develop a patient-oriented mentoring and research program in adult gastroenterology at Baylor College of Medicine. By establishing a methodological and content based program, we will provide mentorship and research opportunities to students, fellows and junior physician and PhD faculty interested in pursuing independent research careers in Epidemiology and Outcomes research in digestive and liver disorders. The proposed program will be interdisciplinary in nature and will be facilitated by the interaction between physicians and scientists in the Sections of Health services Research and Gastroenterology at Baylor College of Medicine. The applicant has MD and MPH degrees and is a gastroenterologist and epidemiologist. He has faculty appointments in both Baylor sections, and is the Chief of the Clinical Epidemiology Division within the Houston Center for Quality of Care and Utilization Studies. His research interests focus on the clinical epidemiology and outcomes of GERD and Barrett's esophagus as well as hepatocellular carcinoma. The proposed program is based on current research projects conducted by the applicant and the planned continuation projects arising from this research, including: (1) Patterns, Determinants, and Outcomes of Screening For Hepatocellular Carcinoma. The aims of this study are to determine the patterns (prevalence, type and frequency) of utilization of pre-diagnosis screening for HCC in patients diagnosed with HCC;to examine the determinants of screening among patients diagnosed with HCC, including patient characteristics, socioeconomic status, and physician provider factors;to examine the patterns and determinants of utilization of potentially curative therapy (resection, transplantation, local ablation) among patients with HCC and to determine the impact of screening on the utilization of HCC therapy;and to determine the impact of pre-diagnosis HCC screening on mortality of patients diagnosed with HCC. (2) Obesity. H. pylori, and the risk of Barrett's esophagus. The aims of this study is to estimate the effects of the amount and distribution of total body fat, as well as abdominal obesity and the serum levels of adipocytokines on the prevalence of newly diagnosed BE;to examine the effect of H. pylori infection on the prevalence of newly diagnosed BE;to estimate the effect of BMI and abdominal obesity and the effect of H. pylori infection on the prevalence of newly diagnosed BE while adjusting for lifestyle, demographic, clinical and histological features;and to estimate the effect of BMI and abdominal obesity and the effect of H. pylori infection on BE tissue COX-2 expression.